For purposes of guiding flow, single-stage and multistage radial compressors in which one or more compressor impellers are arranged on a compressor shaft in a compressor housing of the respective radial compressor have stator component parts which surround the compressor impellers of the respective radial compressor and which are arranged in layers or one behind the other in an axial direction of the radial compressor and together form a stator assembly of the radial compressor.
The stator component part which is associated with a first impeller stage of a radial compressor and which possibly surrounds the latter is also known as an inlet insert and can be constructed, e.g., as inlet heart.
According to the prior art, gaseous fluid, for example, is introduced into a compressor impeller rotating together with a compressor shaft in a compressor housing of the radial compressor via a fluid inlet which is formed in the compressor housing and which can have an inlet connection piece and via a fluid inlet passage which is formed in an inlet insert, and the fluid is conveyed out of the compressor impeller radially into a diffuser passage which directs the fluid into a fluid outlet passage (a spiral passage or collector passage for discharging fluid accelerated by a last compressor impeller) which is formed in a fluid discharge element. The fluid is guided via the fluid outlet passage to a fluid outlet in the compressor housing, which fluid outlet is provided, e.g., with a discharge nozzle, and is supplied to a subsequent process.
Spiral passage refers to a passage which develops or increases in cross section over the circumference of the radial compressor. In contrast, collector space refers to a passage having a constant cross section over the circumference of the radial compressor.
The inlet insert arranged in the compressor housing is commonly produced as a casting, the fluid inlet passage being produced, e.g., by casting cores. However, castings have drawbacks with regard to their lengthy delivery times and the models required for manufacture, which in many cases cannot be reused and which add substantially to production costs for the castings, and with respect to the quality thereof which may vary.
Variations in quality particularly affect dimensional stability (in this case, the dimensional stability of the fluid inlet passage in particular) and material structure which, in the case of castings, can be impaired particularly by casting defects. Casting defects can in turn lead to cracks and to machining problems or can even make it necessary to scrap the entire casting.
As a result, radial compressors which are outfitted with conventional inlet inserts of this kind are problematic for manufacturers of this type of compressor as far as maintaining the required operating characteristics such as operational reliability or fail-safety and meeting agreed-upon delivery times. Accordingly, the production of radial compressors of this kind can entail high cost risks for the producer which manifest themselves, e.g., in contract penalties, increased procurement costs and/or transportation costs, and so on. Moreover, conventional radial compressors of this type are problematic with respect to standardization and thus with respect to cost optimization of the production process.
It is thus an object of the invention to provide a radial compressor of the type mentioned above which has improved operating characteristics over conventional radial compressors and which can be produced with fewer cost risks. It is a further object of the invention to provide a method for the production of a radial compressor of this kind.